This invention pertains generally to computing scales and more particularly to a computing scale which is particularly suitable for postal use.
A number of factors are involved in determining the cost of sending a letter or package from one place to another, including the size and weight of the object, the distance it is to be sent, and the manner in which it is sent. In the past, clerks have had to weigh letters and packages manually, then determine the correct postage from tables or by calculation, then add the charges for any special services desired (e.g., special delivery), and affix the stamps or other indicia that the postage has been paid to the letter or package. This is a time-consuming process and one which is subject to a number of errors on the part of the clerk required to perform the various mechanical operations.
With the advent of computers and calculators, it appeared that at least some of the calculations previously performed manually by postal clerks might be done faster and more accurately on machines. However, a clerk provided with a calculator must still weigh a package or letter manually and obtain information such as postal zone rates from tables, then enter the weight and rate information manually into the calculator.
There have been some attempts to provide computing scales which will weigh a package or letter and then combine the weight information with rate information stored therein to determine the postage. However, postal scales require an accuracy of less than one ounce over a range on the order of 70 pounds, and electronic scales heretofore provided have not been capable of such accuracy.